1. Field of the Invention
The invention relates to a latch mechanism for producing a releasable connection of a housing portion with a further housing portion, projections being provided on one of the housing portions, and for producing a releasable connection by means of a rotational motion of the housing portions relative to one another, the latch projections latchingly engaging in associated latch recesses.
2. Description of Related Art Including Information Discussed Under 37 CFR 1.97 and 1.98
From U.S. Pat. No. 4,600,277, a telescope is known with a main housing and at least two interchangeable monocular systems. The two monocular systems differ definitively in that a first monocular system has a coaxial arrangement or alignment with respect to the optical axis of the telescope. A second monocular system has an angular shape and permits looking into the telescope at an angle of 45° to the optical axis, which is established by the lenses mounted in the main housing. The monocular arrangements can be connected to the main housing or to the telescope, respectively, by means of a bayonet coupling means. The bayonet coupling means includes L-shaped projections on the monocular system. These projections are fixedly connected to the housing of the respective monocular system and have an axial alignment in relation to the optical axis. Recesses are allocated to these projections, and are formed in a plate fixedly connected to the main housing and arranged at right angles to the optical axis of the telescope. The projections and the recesses have different extensions in the peripheral direction in comparison with each other, so that the monocular system can assume only a predetermined and thus defined position when the monocular system and main housing are connected.
For connecting the main housing and the monocular system, the projections are guided in an axial direction through the recesses formed in the plate. The L-shaped projections then clamp behind this plate by means of a rotational motion. For fixing, a pin is provided which latches into a recess provided in the monocular system. To release the monocular system, this pin, which is prestressed by a spring, has to be withdrawn by the user. For this, an operating element is provided which is to be operated by the user for this purpose.
From U.S. Pat. No. 2,260,991, a latch mechanism is known for providing a releasable connection of an objective with a camera housing. In this latch mechanism also, a plate fixed to the camera housing is provided. Recesses are provided in this plate with different extensions in the peripheral direction. Projections facing radially, formed on the objective housing, cooperate with these recesses when producing a fixed connection. To produce the fixed connection, the projections pass through the recesses of the plate connected to the camera. By rotation of the objective, the projections of the objective clamp behind the plate.
In these systems, it is disadvantageous that the projections formed on a component are strongly loaded when latching into the other component such as a main housing or camera housing. On frequent connection and release, damage of the projections results due to this strong loading.